Merge eb976d6 into dd0a007

src/index.js

@@ -11,6 +11,7 @@ import redis from './lib/redisClient';
 import session from 'koa-session2';
 import passport from 'koa-passport';
 import { loginRouter, authRouter } from './auth';
+import lineContentRouter from './lineContent';
 
 const app = new Koa();
 const router = Router();
@@ -36,6 +37,11 @@ router.use('/callback', webhookRouter.routes(), webhookRouter.allowedMethods());
 
 router.use('/login', loginRouter.routes(), loginRouter.allowedMethods());
 router.use('/authcallback', authRouter.routes(), authRouter.allowedMethods());
+router.use(
+  '/getcontent',
+  lineContentRouter.routes(),
+  lineContentRouter.allowedMethods()
+);
 
 if (process.env.NODE_ENV === 'production') {
   app.use(

src/lineContent.js

@@ -0,0 +1,28 @@
+import Router from 'koa-router';
+import { fetchFile } from './webhook/handlers/fileHandler';
+import { verify, read } from 'src/lib/jwt';
+
+const lineContentRouter = Router();
+
+lineContentRouter.get('/', async ctx => {
+  const jwt = ctx.query.token;
+  if (!jwt || !verify(jwt)) {
+    const err = new Error('`token` is invalid or expired.');
+    err.status = 400;
+    err.expose = true;
+    throw err;
+  }
+
+  const parsed = read(jwt);
+  const response = await fetchFile(parsed.messageId);
+  ctx.response.set('content-length', response.headers.get('content-length'));
+  ctx.response.set('content-type', response.headers.get('content-type'));
+  ctx.response.set(
+    'content-disposition',
+    `attachment; filename=${parsed.messageId}`
+  );
+  ctx.status = 200;
+  ctx.body = response.body;
+});
+
+export default lineContentRouter;

src/webhook/handlers/fileHandler.js

@@ -3,6 +3,7 @@ import { google } from 'googleapis';
 import fs from 'fs';
 import util from 'util';
 import { exec as child_process_exec } from 'child_process';
+import { getLineContentProxyURL } from './utils';
 const exec = util.promisify(child_process_exec);
 
 const OAuth2 = google.auth.OAuth2;
@@ -36,7 +37,7 @@ function initGDrive() {
   drive = google.drive({ version: 'v3', auth: oauth2Client });
 }
 
-export async function downloadFile(messageId) {
+export async function fetchFile(messageId) {
   //get line message file
   const LINE_API_URL = `https://api-data.line.me/v2/bot/message/${messageId}/content`;
   const options = {
@@ -80,6 +81,8 @@ export async function saveImageFile(fetchResponse, fileName) {
 }
 
 export async function processImage(messageId) {
+  console.log(`Image url:  ${getLineContentProxyURL(messageId)}`);
+
   const filePath = tmpDir + messageId;
   const command = `tesseract ${filePath}.jpg ${filePath} -l chi_tra`;
   await exec(command);

src/webhook/handlers/utils.js

@@ -1,6 +1,7 @@
 import { t, msgid, ngettext } from 'ttag';
 import GraphemeSplitter from 'grapheme-splitter';
 import { getArticleURL, createTypeWords } from 'src/lib/sharedUtils';
+import { sign } from 'src/lib/jwt';
 
 const splitter = new GraphemeSplitter();
 
@@ -696,3 +697,18 @@ export function createArticleSourceReply(sessionId) {
     },
   };
 }
+
+const LINE_CONTENT_EXP_SEC = 300; // LINE content proxy JWT is only valid for 5 min
+
+/**
+ * @param {string} messageId - The line messageId
+ * @returns {string}
+ */
+export function getLineContentProxyURL(messageId) {
+  const jwt = sign({
+    messageId,
+    exp: Math.round(Date.now() / 1000) + LINE_CONTENT_EXP_SEC,
+  });
+
+  return `${process.env.RUMORS_LINE_BOT_URL}/getcontent?token=${jwt}`;
+}

src/webhook/index.js

@@ -9,7 +9,7 @@ import handleInput from './handleInput';
 import { groupEventQueue, expiredGroupEventQueue } from 'src/lib/queues';
 import GroupHandler from './handlers/groupHandler';
 import {
-  downloadFile,
+  fetchFile,
   uploadImageFile,
   saveImageFile,
   processImage,
@@ -208,7 +208,7 @@ const singleUserHandler = async (
 
       let text = '';
       try {
-        const res = await downloadFile(otherFields.message.id);
+        const res = await fetchFile(otherFields.message.id);
         uploadImageFile(res.clone(), otherFields.message.id);
         await saveImageFile(res, otherFields.message.id);
         text = await processImage(otherFields.message.id);